hwmon: (adt7411) Improve locking
Add proper locking for the cached variables. Also get rid of
ref_is_vdd, which became obsolete.
Signed-off-by: Wolfram Sang <w.sang@pengutronix.de>
Signed-off-by: Jean Delvare <khali@linux-fr.org>
diff --git a/drivers/hwmon/adt7411.c b/drivers/hwmon/adt7411.c
index 9e9246f..3471884 100644
--- a/drivers/hwmon/adt7411.c
+++ b/drivers/hwmon/adt7411.c
@@ -48,9 +48,9 @@
struct adt7411_data {
struct mutex device_lock; /* for "atomic" device accesses */
+ struct mutex update_lock;
unsigned long next_update;
int vref_cached;
- bool ref_is_vdd;
struct device *hwmon_dev;
};
@@ -142,18 +142,18 @@
int val;
u8 lsb_reg, lsb_shift;
+ mutex_lock(&data->update_lock);
if (time_after_eq(jiffies, data->next_update)) {
val = i2c_smbus_read_byte_data(client, ADT7411_REG_CFG3);
if (val < 0)
- return val;
- data->ref_is_vdd = val & ADT7411_CFG3_REF_VDD;
+ goto exit_unlock;
- if (data->ref_is_vdd) {
+ if (val & ADT7411_CFG3_REF_VDD) {
val = adt7411_read_10_bit(client,
ADT7411_REG_INT_TEMP_VDD_LSB,
ADT7411_REG_VDD_MSB, 2);
if (val < 0)
- return val;
+ goto exit_unlock;
data->vref_cached = val * 7000 / 1024;
} else {
@@ -167,9 +167,13 @@
lsb_shift = 2 * (nr & 0x03);
val = adt7411_read_10_bit(client, lsb_reg,
ADT7411_REG_EXT_TEMP_AIN1_MSB + nr, lsb_shift);
+ if (val < 0)
+ goto exit_unlock;
- return val < 0 ? val :
- sprintf(buf, "%u\n", val * data->vref_cached / 1024);
+ val = sprintf(buf, "%u\n", val * data->vref_cached / 1024);
+ exit_unlock:
+ mutex_unlock(&data->update_lock);
+ return val;
}
static ssize_t adt7411_show_bit(struct device *dev,
@@ -199,7 +203,9 @@
ret = adt7411_modify_bit(client, s_attr2->index, s_attr2->nr, flag);
/* force update */
+ mutex_lock(&data->update_lock);
data->next_update = jiffies;
+ mutex_unlock(&data->update_lock);
return ret < 0 ? ret : count;
}
@@ -282,6 +288,7 @@
i2c_set_clientdata(client, data);
mutex_init(&data->device_lock);
+ mutex_init(&data->update_lock);
ret = adt7411_modify_bit(client, ADT7411_REG_CFG1,
ADT7411_CFG1_START_MONITOR, 1);